What are the effects of learning and teaching?

SHAFAQNA – In his letter to his eldest son Imam Hassan (AS), Imam Ali (AS) wrote: Learn the knowledge and science of the one who is learned; and teach your knowledge to someone who does not know. If you do so, Allah (SWT) will teach you what you do not know, and you will benefit from what you know. Therefore, with this action (learning and teaching), you will benefit plenty from knowledge and its rewards [1].